The diagnosis of malaria involves identification of malarial parasite or its antigens/products in the blood - The diagnosis of malaria is confirmed by blood tests and can be divided into microscopic and nonmicroscopic tests.1) Microscopic testFor nearly a hundred years, the direct microscopic visualisation of the parasite on the thick and/or thin blood smears has been the accepted method for diagnosis. The careful examination of a well prepared and well-stained blood film currently remains the "gold standard" for malaria diagnosis.2) Non-Microscopic testsAlthough the peripheral blood smear examination that provides the most comprehensive information on a single test format has been the "gold standard" for the diagnosis of malaria, the immunochromatographic tests for the detection of malarial antigens developed in the past decade have opened a new and exciting avenue in the malaria diagnosis.Immunochromatographic test for malaria antigens -Immunochromatographic tests are based on the detection of the parasite antigens from the peripheral blood using either monoclonal or polyclonal antibodies against the parasite antigen targets.Currently, immunochromatographic tests can target the:-Histidine-rich protein 2 of Plasmodium falciparum Pan malarial Plasmodium aldolase Parasite-specific lactate dehydrogenase. Histidine-rich protein 2 of Plasmodium falciparum (PFHRP2) It is a water-soluble protein that is produced by the asexual stages and gametocytes of Plasmodium falciparum, expressed on the red cell membrane surface and shown to remain in the blood for at least 28 days after the initiation of antimalarial therapy.Plasmodium aldolaseIt is an enzyme of the parasitic glycolytic pathway expressed by the blood stages of P. falciparum as well as non falciparum malarial parasites. Monoclonal antibodies against plasmodium aldolase are panspecific in their reaction and have been used in a combined Rfalciparum/P.vivax immunochromatographic tests that targets the pan malarial antigen along with PFHRP2.Parasite lactate dehydrogenase -The first rapid diagnostic tests were using P.falciparum glutamate dehydrogenase as antigen P.falciparum gutamate dehydrogenase were soon replaced by P. falciparum lactate dehydrogenase. It is a soluble glycolytic enzyme produced by the asexual and sexual stages of the live parasite and it is present in and released from the parasite infected. It has been found in all four human malarial species and different isomers of pLDH for each of the four species exist.Other tests for malaria parasites - Polymerase chain reaction -Polymerase amplification can also be used to detect malarial parasites. In travellers returning to developed countries studies based on PCR have been found to be highly sensitive and specific for detecting all species of malaria particularly in cases of low-level parasitemia and mixed infections. The PCR test is reportedly tenfold more sensitive than microscopy.Detection of antimalarial antibodies -Antibodies to the asexual blood stages appear a few days after malarial infection, increase in titre over the next few weeks and persists for months or years in semi-immune patients in endemic areas where re-infection is frequent. In non-immune patients, antibodies fall more rapidly after treatment for a single infection and are undetectable in 3-6 months. Reinfection/relapse induces a secondary response with a rapidly increasing antibody titre. Malarial antibodies can be detected by immunofluorescence or enzyme immunoassay. It is useful in epidemiological surveys for screening potential blood donors and occasionally for providing evidence of recent infection in non-immunes.Intraleucocyte malarial pigment -Intraleucocyte malaria pigment has been suggested as a measure of disease severity in malaria.FlowcytometryFlowcytometry and automated hematology analyzers have been found to be useful in indicating a diagnosis of malaria. In cases of malaria, abnormal cell clusters and small particles with DNA fluorescence probably free malarial parasites have been seen on automated hematology analyzers and it is suggested that malaria can be suspected based on the scatter plots produced on the analyzer.Mass spectrometryA novel method for the in vitro detection of the malaria parasite at a sensitivity of 10 parasites/ 1 of blood has been recently reported.